06.02.12 8:45 AM ET

Many Americans, children and adults alike, have a weight problem, a fact of life fully evident in any mall in the country. Indeed, American adults have literally packed on nearly 3 million tons of added flab since 1960, with some Americans testing the expansion limits of Spandex and, at the same time, running serious medical risks.

First lady Michele Obama wants to solve the country’s weight problems through education. However, self-appointed fat police (politicians, nutritionists, and obesity researchers) seek more intrusive policies in people’s consumption decisions, especially when it comes to their favored culprit in the country’s “obesity epidemic”: sugared sodas. They’ve long had a favored solution: a penny-per-ounce tax on sugared sodas, which could push up the price of a 12-ounce can of Coke and Pepsi sold at Costco by nearly 40 percent to discourage consumption. Now, New York City Mayor Michael Bloomberg has proposed a ban on the sale of sodas in containers that hold more than 16 ounces in identified venues, from movie theaters to fast-food restaurants. The ban amounts to a hidden tax because, if enforced, it increases the price of 32-ounce drinks by at least 75 percent (since two large sodas would have to be bought).

The fat police make two main arguments for their proposed soda tax. First, cigarette taxes worked effectively, causing millions of Americans to kick their smoking habits. Second, according to recent studies, an increase in the price of sodas by one cent per ounce would reduce the cans sold in the United States by 10 to 25 percent, which, supposedly, would lower the prevalence of obesity by 1.5 percent and save maybe 2,600 lives a year (hardly stunning findings, which are likely overstated). The banning of Big Gulp-size sodas in movie theaters must be at least as effective as soda taxes, or so Mayor Bloomberg would like his constituents to believe.

To put it bluntly, soda bans and taxes are policy snares and represent a monumental threat to Americans’ treasured freedom to eat and drink what they—not government bureaucrats and politicians—want. The most notable reason soda bans and taxes will fail miserably is, ironically, a key research finding known to advocates of the soda tax: “[T]he association between soda sales taxes and the state-level prevalence of obesity has been found to be weak,” and there are solid reasons for the statistical disconnect in the advocates’ case for favored soda taxes and bans.

AFP / Getty Images (2) ; AP Photo (2)

First, there are unlimited sources of sugar and fat. If you tax one sugared product, you make the targeted products less attractive–but you also make any number of other sugared products relatively more attractive. If theaters are limited on the size drinks they can sell, they can offer free refills, and throw in “free” candy bars with their large-soda purchases, or offer a buy-one-get-one-free deal. With narrowly targeted bans, people can still get their sugar fixes from a multitude of other venues and sources that are not subject to bans (grocery and convenience stores are not covered). Twinkies, anyone?

Indeed, targeted taxes and narrowly focused bans on offending sodas (and foods) can cause many Americans to consume even more sugar, which means to effectively combat the country’s weight problems, bans and taxes must be ever more expansive and intrusive on individual choices for all Americans.

Soda bans and taxes are a slippery policy slope toward the “Nanny State,” with the fat police telling the rest of us what not to eat and drink. They really do want people to believe that all fat people are miserable (and stupid), which is hardly the case. Many, no doubt, are, but many don’t fit the mold. Just look around.

Second, in the case of tobacco bans and taxes, the bans and taxes could be narrowly targeted and were, and are, endured solely by the offending parties—smokers. Soda (and other fat) bans and taxes will certainly hit the supposed offending parties, but they will also be paid by people who work hard–and suffer real costs—to remain trim. They can also have unintended and unanticipated consequences. Ironically, as research has shown, higher cigarette taxes have contributed to the country’s weight gain by causing reformed smokers and never-smokers to eat more than they otherwise would have.

Instead of narrowly focused or blanket bans and taxes on identified categories of sugared and fatty foods, a far more direct and effective policy course would simply be to hold heavy people fully responsible for the costs of their excess poundage. These weight-related costs show up in lost productivity and higher medical costs and in their impositions on others’ space in the tight quarters of planes and buses. Having heavy people bear the full costs of their excess poundage (for example, through lower wages and higher insurance premiums and air fares) will surely be far more freedom preserving and effective in curbing obesity than soda bans and taxes.